High-speed rotating apparatus



March 23, 1965 TAKU RO SU DO ETAL HIGH-SPEED ROTATING APPARATUS FiledNov. 20, 1962 Fig@ I@ .zz J2 d? L L L \l R, R2 E@ :I x :I SVB CL Reg Tebe h IVL` A FT; 54, LEGEND 194 osclLLATloN VOLTAGE D L5 gg g L xsoLARBAUERY L; 04 GENERATED VOLTAGE oscLLLATLoN FREQUENCY 03 G E g1200 502 t//0 'n' moo 0 Q00 2000 3000 4000 INTENSITY 0F ILLUMINATIUN/(lux) UnitedStates Patent Office 3,174,34l Patented Mar. 23, v1965 3,174,341HIGH-SPEED ROTATING APPARATUS Taliuro Sudo, Musashino-shi, Tokyo-to,Saburo Chiba,

Setagaya-ku, Tokyo-to, and Yasuyuki Goto, shimaslri, Tokyo-to, Japan,assignors to Kabnshilii Kaisha Hitachi Seisalmsho, Maruuouchi,Chiyoda-ku, Tokyoto, Japan, a joint-stock company of Japan Filed Nov.20, 1962, Ser. No. 239,401 Claims priority, application Japan, Nov. 22,1961, 25o/41,758 4 Claims. (Cl. 73-351) This invention relates tohigh-speed rotating apparatuses, and more particularly it relates to anew high-speed rotating apparatus provided with a unique and effectivetemperature-detecting system.

In such a high-speed rotating apparatus as an ultracentrifuge, whereinvarious macromolecular solutions or collodial solutions are subjected tohigh centrifugal force to accomplish Aseparation .and reiinernent ofline particles, or wherein, by optically measuring the velocity ofmovement of molecules within a solution placed in a centrifugal eld anda concentration distribution of the said molecules within the solution,the molecular weights and distribution of molecular weights of themolecules are determined, the detection and control of the sampletemperature are important requirements. In spite of these requirements,problems such as those described hereinbelow arise, and the detecting ofthe temperatures within such a high-speed rotating apparatus hasheretofore been extremely difficult.

That is, While the velocity of movement of the abovementioned solutemolecules varies with variation in such factors as the magnitude of thecentrifugal force, the concentration, and the temperature, a highcentrifugal force is considered to be necessary for separating solutemolecules of especially low molecular weights. To satisfy thisrequirement, it would be necessary to exert, continuously, a centifugalforce of the order of approximately 2.6 108 gram.centimetensecend-z,ordinarily, with a practical ultracentrifuge. From this necessity, suchdifficulties as the following two arise. In the lirst place, atemperature-detecting element for temperature measurement which is to beattached to such a high-speed rotating body must be capable ofwithstanding such high-speed rotation as described above and must detecttemperatures accurately. In the second place, the temperature-detectingsignal output from the temperature-detecting element provided on therotating body must be transmitted in a relatively easy manner to atemperature indicating and controlling device xed on the outside of therotating body.

It is a prime object of the present invention to solve theabove-described problems.

It is a specific object of the invention to provide a new high-speedrotary machine provided with an eiective thermometric device.

The nature, principle, and details of the invention will be moreclearlyaparent from the following detailed description of onerepresentative embodiment of the invention taken in conjunction with theaccompanying drawings in which like parts are designated by likereference nume-rals and letters, and in which:

FIG. 1 is an elevational View, partly in section with parts cut away,and partly in schematic form, showing the embodiment;

FIG. 2 is an enlarged elevational view, partly in section with parts cutaway, showing principal details of the lower part of the embodiment ofFIG. 1;

FIG. 3 is an electrical circuit diagram showing the composition andarrangement of one example of an oscillator for temperature measurementsuitable for use in the present invention;

FIG. 4 is an electrical circuit diagram showing another example of anoscillator for temperature measurement suitable for use inthe presentinvention; and

FIG. 5 is a graphical representation indicating the characteristics ofthe oscillator and power source indicated in FIG. 4.

Referring to FIG. l, the principal mechanical part of the embodimentshown, which is in the form an ultracentrifuge, is a rotor 1 providedwith a sample cell 2 which is for containing a sample and is transparentin the direction parallel to the rotor axis. The rotor 1 is enclosed byand supported rotatably in an airtight housing or chamber 3, theinterior of which is evacuated by a vacuum pump 4 to approximately l0-8mm. Hg vacuum so as to facilitate the high-speed rotation of the rotor.The rotor 1 is rotationally driven by a driving system 5 coupled theretoand is cooled by a cooling coil 7 which is disposed about, but somewhatseparated from, the rotor l, and which is connected to a cooling device6. The vacuum chamber 3 is further provided on its upper and lower wallswith optical Windows It) and 9, which are so disposed on the samevertical axis passing through the sample cell 2 that light emitted froma light source S for sample analysis passes successively through theWindow 9, the sample cell 2 (and, therefore, the sample), and the windowlil to be projected by way of a refiecting mirror 11 to an opticalapparatus t2 for observation and measurement, by which analysis ofthesample is accomplished.

The rotor 1 is provided at its base part With a temperature-detectingoscillator 13, the constructional details of which are shown in FIG. 2.An insulating platform i4 which supports a solar-battery 24, lightsource container 15 below and coaxially with the oscillator 13 isrigidly mounted on a support lixed to the bottom of the vacuum chamber3. The output of the oscillator 13 is led out through an airtight,insulated terminal 16 provided on a wall of the vacuum chamber 3 to anamplifying device 17. The output of this amplifying device 17 istransmitted to a temperature-measuring device 18, which measures thesample temperature through the frequency of a temperature-detectionsignal. The details of temperature-measuring system will be described indetail hereinafter. Although the specific details are not indicated inthe drawings, it will be obvious that it is possible to set and maintainthe sample temperature within the rotor at a desired value by adaptingthe aforsaid cooling device 6 and a heating device I9 having aring-shaped heating element to be controlled by the output of theaforesaid temperature-measuring device 1S.

The detector of the apparatus according to the invention consists of anelectronic oscillator. Since means are provided to cause a signal to` betransduced by deviations in the oscillation frequency of this electronicoscillator, it is possible to use an electrostatic coupling system ofrelatively simple arrangement as the coupling means, necessary fortransducing oscillation power, between the rotor and the stationary partof the apparatus. Although various transducing methods, such as anelectro magnetic coupling method or a method wherein oscillation poweris caused to be radiated by means of an `antenna and received on thestationary side, may be considered for adoption Ias the aforesaidcoupling means, an electrostatic coupling system formed merely bymutually-facing, parallel electrode plates is used in apparatus of thisinvention, Accordingly, it is an advantageous feature of the inventionthat a simple construction suffices for this coupling means.

Furthermore, since the detector oscillator of the appar-atus of thisinvention is adapted to utilizeV a photocell such as, for example, asolar battery, which is capable of withstanding high-speed rotation andis, moreover, of small size, as its power source, it does not require acoupling means or wire especially for receiving power from outside ofthe high-speed rotating body. Moreover, this oscillator has a circuitarrangement enabling it to operate with ample stability by means of lowoutput such as that of a solar battery as will be described in greaterdetail hereinafter.

This important detector oscillator, its power source, and theoscillation power transducing system will now be described in detail.Referring to FIG. 2, which shows the details of the afore-mentionedsolar-battery light source section and the detector oscillator sectionprovided in the base part of the rotor, the detector oscillator properis installed in a hollow 2l formed in the bottom of the rotor base,coaxially at the center of rotation. Accordingly, in spite of thehigh-speed rotation of the rotor, this oscillator Ztl is unaifected bythis rotation. For the power source for the detector oscillator, thereis provided, at the base part of the rotor, a solar battery 24, which isadapted to be constantly irradiated by light from a light source 22through a lens 23, the said light source 22 and lens 23 being enclosedand supported in the aforementioned light source container l5. The solarbattery 24 is protected by a protective, transparent glass plate 25disposed therebelow.

The output of the detector oscillator is led out, through anelectrostatic coupling consisting of a ring-shaped, planar electrode 26fixed coaxially to the bottom of the rotor base and an electrode 27fixed to the insulating platform 14 in a disposition which is parallelto and coaxially facing the said electrode 26, then through anelectrostatic coupling output terminal 23, to the aforo-mentionedtemperature-measuring device.

One example of an oscillator of impedance tapered, three parallelphase-shift, R-L type which is suitable for use as the detectoroscillator of this invention is illustrated in FIG. 3 and is arranged inthe following manner. A phase-shift type, R-L circuit composed ofresistance elements R1, R2, and R3 and inductance elements L1, L2, andL3 is inserted between the collector output side and emitter input sideof a base-grounded type transistor TI. so as to constitute a positivefeedback circuit on the emitter side and form a current typeamplification section. At the same time, the value of each of the timeconstants L1/R1, Lz/Rg, and {Z3/R3 of the circuit elements is suitablyselected so as to cause the necessary amplification of the feedbackcircuit to be less than unity and the phaseshift to be zero.Accordingly, the instant circuit is an extremely eifective circuit as adetector oscillator for the apparatus of the present invention becauseit possesses the following characteristic features.

(l) Since this circuit incorporates a base-grounded type, single-stageamplitication circuit, its composition is simple and requires smallphysical space, as in the case of the single-base-common typetransistor, R-C and R-L oscillators described in the specification ofJapanese patent application No. 39,034/ 1960. At the same time,moreover, the operation of this circuit is extremely stable. Forexample, the operation can be easily maintained with a stabilitycorresponding to a frequency deviation of the order of with respect to avariation in irradiation of the order of i2() percent of the lightsource for irradiation of the solar battery. Therefore, it is possibleto utilize a relatively high signal-noise ratio.

(2) Because an R-L circuit is used for the phase-shift circuit, andpower is supplied through the inductance L, a low direct-current voltagedrop due to the load of the ampliiication section sumces. Accordingly,since it is possible to use a low power-source voltage, a solar batterycan be used as a power source capable of withstanding high-speedrotation, and the circuit can be operated with the low output power ofthis solar battery with ample ture.

where f is the oscillation frequency, and

L1 L2 L.;

lf each of the inductances L1, Lg, and L3 are constant,

and each of the resistance elements R1, R2, and R3 is a thermistorselected to have a suitable value, the rates of variation of resistanceof these thermistors will be the same when the surrounding atmospherictemperature changes, and the above equation becomes:

where k is a constant.

As is apparent from this equation, the oscillation frequency will thenvary linearly with the temperature, whereby the design of thetemperature-detecting circuit will be facilitated.

(4) Furthermore, because the detector oscillator is assembled in amicro-miniaturized manner, and the entire oscillator including thethermistors which constitute the main temperature detection device isadapted to operate as a temperature detector, the drift characteristicsof the oscillation frequency with respect to temperature variation ofthe transistor circuit itself, when the said thermistors are consideredto be resistance elements which are unrelated to temperature, need notalways be flat. That is, even if the above-said drift characteristicsexist, the temperature characteristic due to the use of t'hermistor ofhigh temperature coefcient for the resistance element RY has a higheryabsolu-te value and, moreover, corresponds to a straight line having asteep slope, and its oscillation frequency characteristics has asubstantially constant tendency with respect to temperature variation.For this reason, temperature compensation of the transistor circuititself is not especially required, wherefore the design is facilitated.

Another example of a practical circuit suitable for the detectoroscillator of the instant apparatus, as shown in FIG. 4, is an L-C typeoscillator comprising a tunnel diode TD, inductances L4 Iand L5,capacitors C1 and C, and -a solar battery SB. This circuit has thefollowing characteristic features.

(l) The composition of this circuit is simple, and the oscillationfrequency can be easily maintained constant because thenegative-resistance characteristics of the tunnel diode TD arerelatively stable with respect to tempera- Especially, since the workingvoltage of this tunnel diode is low, it is possible to use an extremelyminiature power source.

(2) Since an L-C oscillation circuit is used and adapted to be suppliedwith power through the elements L, it is possible to use a solar batteryfor the power source similarly `as in the case illustrated in FIG. 3,and a power supply line from the outside is not particularly required.

(3) For the capacitors C, barium titanate porcelain having 4a dielectricconstant which varies, in relatively sharp state, with the temperaturevariation is used. Therefore, the increment of oscillation frequency,that is, the increment of detection signal, with respect to temperaturevaria-tion can be made large, as indicated Iby one example of actualmeasurement in which a dielectric constant of o 1000 pf. at l degrees C.became as lo-W -as 100 prf. at 85 degrees C. Accordingly, it is possibleto make the signalto-noise (S/N) ratio substantially large.

FIG. shows curves indicating actual measurements of the electromotiveforce characteristic of the solar battery and the oscil'lation frequency`characteristics and oscillation output characteristic due to theoscillation circuit shown in FIG. 4 with respect to variation inintensity of illumination of a tungsten lamp used as .the irradiationsource of the solar battery. As shown by these curves, although theelectrornotive force or voltage of the lsolar battery varies withvariation in intensity of illumination, the curves of oscillationvfrequency and oscillation -amplitude characteri-stics exhibitsubstantially tlevel characteristics in the vicinity of an intensity ofillumination of approximately 2200 lux. Therefore, when the intensity ofillumination is set `at approximately 2200 lux, even if someillumination change occurs, fluctuations in the oscillation frequencyand Ithe oscillation amplitude due to this illumination change can bekept small. The curves sho-wn in FIG. 5 were obtained by actualmeasurement in the case of a cir-cuit according to FIG. 4 in which01:0.1 pf., C=SO pf., Llili() ph., and [qe-220 ph.

The detection signal output obtained in afore-described manner istransmitted, through the electrostatic coupling device consisting ofparallel-plate electrodes 26 4and 27 and the terminal 23, to thealternating-current yamplifying device 17. This alternating-currentamplifying device 17, as a high-input impedance, minimizes the reactanceeffect of the aforesaid electrostatic coupling device. The sampletemperature is measured through the magnitude of lthe output of theramplifying device 17. At the same time, this output can be utilized tocontrol the sample temperature to any desired value as was describedhereinbefore.

As is apparent from the Iforegoing description, the apparatus of thisinvention is provided with a microminiature oscillator of L-R or L-Ctype which has relatively high operational stability andtemperature-detecting sensitivity, land which is easily operated by anextremely low vol-tage, and with la solar battery for the power sourceof this oscillator. Moreover, the output of this oscillator is led outthrough a simple, electrostatic coupling device. Accordingly, thepresent invention provides a high-speed rotating apparatus wherein, bymeans of a relatively simple yet strong construction, measurement andicontrol of the temperature of a sample in its high-speed rotating bodycan be easily and effectively accomplished.

Since it is obvious that many changes and modifications can be made inthe above-described details without departing Ifrom the nature andspirit of the invention, it is to be understood that the invention isnot to be limited to the details described herein except as set forth inthe appended claims.

What is claimed is:

l. A high-speed rotating apparatus comprising a highspeed rotating body,a stationary structure, and a thermometric system lfor continuouslymeasuring the temperature w-ithin the said rotating body, the saidthermometric system consisting of ya transistor, R-L type oscillator,which is positioned at the central portion of 4said rotating body, andin which an R-L type passive network composed of at least three stagesof temperature-sensitive resistance elements R and inductances L isinserted in the Output side `and the input side of ia single amplifierconsisting of one base-grounded type transistor element, a positivefeedback is established from one element of the said passive network tothe emitter input side, and the impedance ratio of each of the elementsof the said passive network is so selected that the requiredamplification becomes less than unity, a radiation electromotive torcedevice positioned at the central portions of the said rotating body,measuring means provided outside of the said rotating body, Iand anelectrostatic coupling device, consisting of a conduct-ive rota-tingelectrode provided on the said rotating body and a conductive stationaryelectrede provided on the said stationary structure and disposed to`face the said rotating electrode, for leading out the output of thesaid oscillator -to the said measuring means.

2. A high-speed rotating apparatus comprising a highspeed rotating body,a stationary structure, and a ther-mometric system for continuouslymeasuring the temperature within the said rotating body, the said.thermometric system consisting of yan L-C type oscillator which ispositioned within, and coaxially with the rotation-al axis of, the saidrotating lbody and is provided with a tunnel diode, inductances L andcapacitances C of high capacitance-temperature variation rate, aradiation electromotive force device positioned on, Iand coaxially withthe rotational axis of, the said rotating body, a measuring meansprovided outside of the said rotating body, 'and -an electrostaticcoupling device, consisting of a conductive rotating electrode providedon the said rotating body and a conductive stationary electrode providedon the said stationary structure and disposed to face the said rotatingelectrode, iior leading out the output of the said oscillator to thesaid measuring means.

3. A high-speed rotating apparatus comprising a highspeed rotating body,.a stationary structure, and a thermometric `system for continuouslymeasuring the temperature within the said rotating body, the saidthermometric system consisting of an L-R type oscillator which is variedin its oscillation frequency in accord-ance with the ternperaturevariation and is positioned within center portion of the said rotatingbody, a radiation electromotive force device positioned within thecenter portion of the said rotating body, measuring means providedoutside of the said rotating body, and an electrostatic coupling deviceconsisting of "a conductive rotating electrode provided on Ithe saidrotating body and la conductive stationary electrode provided on thesaid stationary structure Iand disposed to face the said rotatingelectrode, for leading out the output of the said oscillator to the saidmeasuring means.

4. A high-speed rotating apparatus comprising a highspeed rotating body,a stationary structure, and a thermometric system for continuouslymeasuring the temperature within the said rotating body, the saidthermometric system consisting of an L-C type oscillator which is variedin its oscillation Ifrequency in accordance with the temperaturevariation and is positioned within center porton of the said rot-atingbody, a radiation electromotive force device positioned within thecenter portion of the said rotating body, measuring means providedoutside of the said rotating body, and an electrostatic coupling deviceconsisting Ioi a conductive rot-ating electrode provided on the saidrotating body and a conductive stationary electrode provided on the saidstationary structure and disposed to lface the said rotating electrode,for leading out the output of the said oscillator to the said measuringmeans.

References Cited by the Examiner UNITED STATES PATENTS 2,370,818 3/45Silverman. 3,029,642 4/62 Bunhans et al. 73-362 OTHER REFERENCES Hiatt,C. W.: Rotor Temperature in the Ultracentriiuge; in Review of ScientificInstruments (24, 2), pp. 182-183, February 1953.

ISAAC LISANN, Primary Examiner.

1. A HIGH-SPEED ROTATING APPARATUS COMPRISING A HIGHSPEED ROTATING BODY,A STATIONARY STRUCTURE, AND A THERMOMETRIC SYSTEM FOR CONTINUOUSLYMEASURING THE TEMPERATURE WITHIN THE SAID ROTATING BODY, THE SAIDTHERMOMETRIC SYSTEM CONSISTING OF A TRANSISTOR, R-. TYPE OSCILLATOR,WHICH IS POSITIONED AT THE CENTRAL PORTION OF SAID ROTATING BODY, AND INWHICH AN R-L TYPE PASSIVE NETWORK COMPOSED OF AT LEAST THREE STAGES OFTEMPERATURE-SENSITIVE RESISTANCE ELEMENTS R AND INDUCTANCES L ISINSERTED IN THE OUTPUT SIDE AND THE INPUT SIDE OF A SINGLE AMPLIFIERCONSISTING OF ONE BAG-GROUNDED TYPE TRANSISTOR ELEMENT, A POSITIVEFEEDBACK IS ESTABLISHED FROM ONE ELEMENT OF THE SAID PASSIVE NETWORK TOTHE EMITTER INPUT SIDE, AND THE IMPEDANCE RATIO OF EACH OF THE ELEMENTSOF THE SAID PASSIVE NETWORK IS SO SELECTED THAT THE REQUIREDAMPLIFICATION BECOMES LESS THAN UNITY, A RADIATION ELECTROMOTIVE FORCEDEVICE POSITIONED AT THE CENTRAL PORTIONS OF THE SAID ROTATING BODY,MEASURING MEANS PROVIDED OUTSIDE OF THE SAID ROTATING BODY, AND ANELECTROSTATIC COUPLING DEVICE, CONSISTING OF A CONDUCTIVE ROTATINGELECTRODE PROVIDED ON THE SAID ROTATING BODY AND A CONDUCTIVE STATIONARYELECTRODE PROVIDED ON THE SAID STATIONARY STRUCTURE AND DISPOSED TO FACETHE SAID ROTATING ELECTRODE, FOR LEADING OUT THE OUTPUT OF THE SAIDOSCILLATOR TO THE SAID MEASURING MEANS.